Captain Obvious

And here's something that has been bugging me that I just put my finger on... Those are not the original carbs on that car. The carbs on there now are from 72 and are three screw round tops. Original unmolested, survivor, "time capsule", huh? So when the listing says "The numbers-matching 2.4L L24 inline-six was factory rated at 150 horsepower at 5,600 rpm and 146 lb-ft of torque at 4,400 rpm. During current ownership, the carburetors have been cleaned and adjusted" So that may all be "true"... The block may be the original block, and the current carbs may have been cleaned and adjusted, but that doesn't mention the fact that the sometime in the past, the original carbs have been removed and replaced with a different set from a different year. So with just 31K miles, I ask... "Why? And by whom?" I didn't look through all the receipts and records of work done. Is there mention of that anywhere?

All that stuff is stock 73 / 74 flat top gala. 73 was the first year for EGR and they ran coolant through the balance tube to cool the EGR gasses. And as for the other thing you highlighted... Yes, it's an air injection system to pump air directly into the exhaust stream to continue combustion. Not positive what year they started that, but it was present by 72. I'm guessing everything you've ever looked at closely already had headers and round tops?

Perfect. And in case you haven't put numbers on it yet... The 280Z throttle body mounting bolt pattern is a 60mm square. I'm running the previous generation Sentra (96-98) throttle body on my 280 because it has roller bearings and vacuum seals on the throttle shaft. It doesn't breath any different, but it's much smoother and is a little more reliable at idle.

Yes. Way too fresh. Like someone put them there a few years ago when they learned they should be there. Like they took off the appropriately aged hardwares, blasted them shiny, put them back on, and then slathered on the yellow stripe to "look like it just came off the factory line". Problem is that when you blast the plating off hardware like that it rusts. Quickly. There are some spots on the car that look their age. And it is my belief that it if weren't for significant clean-up and repainting efforts, the rest of the car would look like that too. So are any of these questions being raised over at BAT? I didn't see anything. Maybe I'm the outlier and everyone else thinks the car is jaw dropping original.

Yeah, the 240's a different in that regard. The 260 and newer all used a metal bulkhead feed through piece for the water to the core, but the 240 did not. They ran the rubber hoses right through the firewall.

Glad to help. So I went back through my notes, and I cannot be 100% sure that the mounting holes are the same as the Z intake manifold. I think they are, but my notes are inconclusive. I messed around with one of those in a junkyard, but (since I wasn't interested in DBW) I didn't buy it and bring it home. I believe I compared it to an earlier Sentra TB (which I AM positive is the same mounting pattern) and it was the same, but not 100% sure. Just don't want you to waste money on my account. And same thing for the butterfly plate diameter. I believe it's the same 50mm as the stock Z plate, but can't guarantee it. In this case, it would be better if I were wrong and it were actually larger... In any event, might be worth a trip to a junkyard to get some measurements?

Hahaha!!! Do you remember the Chameleon XLE?

Here's a couple pics of what I'm talking about. Not completely sure of the years of application, but it looks like this. The heat sink thingie on the right is the DBW actuator. And here's some pics from ebay, etc. The connector has six connections in it. I'm assuming the TPS feedback element is built into the same section, so some of the wires would be for DBW and some of the others are for TPS feedback. So maybe you could move the actuator over to a different throttle body, or if there is enough meat, maybe you could bore this one out to your liking?

Now you see, I was going to say something like "Wow... The underside looks way worse than the topside." but I didn't want to potentially insult your (or your car). It looked disproportionately bad under there, but I bit my tongue and tried to keep it functional to hide my disappointment. I won't make that mistake next time.....

That diaphragm device is your anti-backfire valve. The round top cars used something similar. Not located in the exact same spot, but pretty close. As for the vacuum line, that went to your "idle compensator" device built into the air cleaner. It's job was to lean out the idle mixture a little bit when the engine got hot. The round top cars didn't have anything like that and you can just pull the hose off the balance tube and put a cap over the nipple.

I know the Sentra went to DBW in like 99 or something and that throttle body uses the same bolt pattern. But I think the throttle plate is same as stock which is too small for you.

Yeah, a lot of individual parts "say" just 31000 miles, but to me, it looks like someone spent a whole lot of time trying to achieve that. Like @inline6 above, I've got a whole host of "Yeah, but then why does this look like this?" situations all over the car. He hit some of them, but I've got others as well. Things like: Dented frame rails, control arms, and floors. Impossibly shiny clean yellow paint marks gratuitously applied on rusted hardware that has had the original plating stripped off. Many other hardware pieces where the original plating has been stripped off or painted over with silver paint. Adjustment witness marks on things that just should never have needed to be adjusted like the door latches. Smeared screw heads on things that should have never needed to come off a 31K mile car like the hood prop arm. I see a well kept Z wearing a well done, but many year old repaint. I see a beautiful Z that I would love to own, but I do not see a survivor.

That's fair.

OK, OK... So it did happen. Thanks for the pics. It looks like you're headed for the typical floor and frame rail work. How about the more complicated areas like the doglegs. They look OK?

There are similar clips used on the Z to hold the heater air box clamshell together. Not sure they're the exact same clip, but the same idea at least.

Since the hatch lock linkage doesn't see any rotational torque force, I think a sloppy hole fit on the back of the cylinder would be fine. You need it to be drawn tight against the back of the cylinder, but the mounting screw takes care of that. I think that hole could be a really loose sloppy fit on the back post and it would still work. You wouldn't be able to do that on the doors because you have to rotate them to get actuation, but on the hatch, that's not the case. It's push to actuate. And when you lock the hatch, it just turns the cylinder so that linkage misses it's target and just waves in the air. So there's no issue there either. It's not like that linkage blocks anything... it misses.

Why don't you just use a small flat or square file to file the current rectangle to fit ninety-degrees? Like this. Won't be quits as strong as original, but with a washer under the head of the clamping screw, it ought to work:

LOL. You guys are fun. Looking forward to the pics! Whatever they turn out to be! Haha!!

Well I got no dog in this fight, but I really don't think that's original paint. There's just too many flags all over the place. In the auction, they never say it has original paint. They do, however, say the following: "The seller reports that a scratch on the right fender and paint chips on the right door were blended in. More than 45 paint-meter readings provided in the photo gallery below show thicker measurements in the aforementioned areas." So what does that mean exactly? To me, that means "We took paint thickness measurements from all over the car and everything looks about the same thickness with the exception of the right side door and fender. Seller reports that those areas were sprayed to fix some issues." I don't think that means the rest of the car is original... All that means is that the rest of the car is CONSISTENT. Like maybe the whole car was sprayed at least once some time in the past, but then the right side was done again? Makes me wonder what the paint thickness would be on a confirmed original paint survivor. Would it be half the thickness they got all over that car? I saw the heater core looped too and I'm guessing the heater core is leaky.

Yeah, that's one of the reasons I'm wondering if everyone is in agreement that it's original paint. It's certainly a beautiful car and I'm no expert on what should/could be painted, but I see stuff that makes me wonder.

Are we sure that is original paint?

I agree with granny above that hub-centric location could/should be more accurate than stud located if the car you're working with was designed to be used in that way. The problem as I see it is... The Z is not designed for that. (Unless you manage to catch the small lip right near the base of the post) the front hubs have that tapered rough cast surface on the center bearing post. That center of the original hubs might run perfect in the center, or it might not. It certainly wasn't machined to guarantee that it would: And the rears have a machined center area, but I think it may be too short to reach deep enough into wheels to do any registration?

Good pics. I can't tell if the needle depths are spot from just pics, but they look good to me. The typical mistake is that they are installed with no shoulder visible and you do not have that issue. They're at least close, so that's good. As for which needle it is, I think it's worth a phone call. Many people replace the original N-27s with SM needles. Some people end up with great results doing that and others end up running rich with the SMs.

Yes, the part number is written on the fat end of the needle, and yes you need to pull them out to read them. That said, however... I wasn't thinking you needed to go out and pull the needles right away. I was thinking more along the lines of looking at the literature that came with the carbs from the company that rebuilt them and seeing if there was a listing on there of what needle they used. Failing that, a phone call to the co. would be my next idea. As far as the installation depth goes, you ought to be able to see needle by looking down into the carb throat. Might need a little right angle inspection mirror to see deep enough, but you ought to be able to see if the needles are installed to the proper depth without too much muss/fuss. And if you can't get a good view of them that way, all you have to do is pull the suction cover off and pull the piston out of the carb for a look. Worst thing that would happen is you might have to replace some damper oil if you spill it.

Yes, that's what I'm saying. I have no reason to believe that thing is anything other than a simple pressure (or lack thereof) switch. If it were my car, I would put that device in a jar and try to draw a vacuum on it and see what happened, but if I could not get that to work, I would just short the connections and see what happened. Unfortunately I don't know if you would hear or smell any difference... The effect may be subtle enough that you might only be able to see it with diagnostic equipment.